Stencil cutting method and ribbon



July 20, 1943. v M, AARON V2,324,662

STENCIL CUTTING METHOD AND RIBBON Filed Feb. 24, 1941 vll/111111111 #Hor/nys Patented July 20, l1943 `l uNi'rED STATES 'PA'IENTV ori-ice 2,324,332 l s'rENcn. currmc muon AND mno l Meer. Aaron, Denver, cui. Application February 24, 1941, serial No. 380,160

This invention relates to the cutting of stencils of gelatin, cellulose and the like, for use 4in a conventional manner to reproduce, in multiple.

, the characters imposed on such stencils, and particularly to a method of performing such cuti ting and to a ribbon'for use in such performance.

'I'his application is a continuation-impart of application, Serial No. 323,574, flied March 12, 1940.

Objects of the invention are to provide:

(a) An improved method of cutting stencils which is particularly adapted for practice through conventional and. readily available agencies such,

' of the face of the stencil-cutting instrument from contamination bythe stencil material, while preserving clear definition of the characters eut in the stencil; v

(d) A strip or ribbon of material and structure adapted `'for use in cutting stencils by typewriters and the like and, in so doing, to provide thev advantages incident to the practice of said method; v

(e) An uninkable ribbon for typewriters and the like having a bodyof exceedingly thin, flexible material with reinforced edges;

(f) A ribbon for typewriters and the like having its body formed in two (2) parallel, interconnected strips, one of which strips is composed of exceedingly thin,` flexible, uninkable material with reinforced edges.l

With the foregoing and other objects in view, all of which will more fully appear rin the following specification, my invention consists in the nature, character and sequence of steps or operations and in the constructions, Acombinations and arrangements of parts and' in the product, all as hereinafter described and claimed and as illustrated in the accompanying drawing in which Fig. 1 is a diagrammatic, isometric illustration of elements assembled for the practice of my method. l

Fig.' 2 is an end View of the assembly illustrated at Figrl.

Fig. gt3 is a view on an enlarged scale, similar to Fig. 2, andy illustrating the cooperative asso-y ciation of the elements of said Fig. 2 at the inv stant of a stencil cutting operation,

Fig. 4 is a conventionalized.V isometric showing of a ribbon and spool assembly conveniently employed for practice of my method in association with typewriters.

Fig. -5 is a fragmentary, detail elevation of an alternative form of ribbon employable in the prac-y tice of the invention. y

Fig. 6 is a view similar to Fig. 5 illustrating another alternative form of ribbon.

Fig. 7 is airagmentary, detail elevation of my improved, reinforced, simple, stencil cutting 'ribbon.

Fig. 8 is a view like Fig. '7 but illustrating a double strip ribbon, the edges of the stencil Outting strip being reinforced.

Figs. 9, 10 and l1 are respectively sections on :lines 9--9 and Illi0 ofFlg. 7 and line II-il y and to other machines will be obvious to those skilled in the art from the following description in the terms of use upon the ordinary gelatin and cellulose stencils in the ordinary typewriting machine.

The mechanical and manual operations of cutting such stencils` upon typewriters are so generally well understood that detailed description l thereof isdeemed unnecessary.

The fouling of the type face by the stencil 4- material when the type face was permitted to come in direct contact .with the stencil, was early recognized as a diiilcultywhich would have -to be overcomel ln order to makel stencil cutting eilicient and practical and it has therefore long' been the practice to provide means between the stencil and the type face designed to prevent such fouling but still permitting the type face to cut the character in the stencil. The common means for this purpose has been a cover sheet of tough, transparent and glazed material overlying the surface of the stencil which is to be cut by the type face so Athat the type face will be separated from the stencil material by the cover sheet and because of the thinness of the cover sheet the type face will actually cut the character in the stencil, acting through the cover sheet for this purpose.

Such a cover sheet has numerous disadvantages among which are the glazed surface of such sheet which produces high lights and reflections, the necessity of removal of the cover sheet from the stencil, replacement of the cover sheet on the stencil and proper replacement in the typewriter in order to make corrections, the tendency of the cover sheet during the cutting operation to bestretched and pulled across the space between adjacent stencil cuts resulting in blurring and deforming the marginscf the cuts, the tendency of the sheet to adhere to the face of the stencil and in the cuts, etc.

By the use of the method, structures and products of the present invention, the disadvantages of the cover sheet, are obviated, all of its advantages are preserved and further benefits are obtained. v

The use of an exceedingly thin, tough and flexible material in the form, manner and stead of an the ribbon at the point of contact of the type face with the stencil sheet and thus eliminates the pulling or stretching of the protective material and the resultant blurring or deforming of the margins of the characters cut in the stencil, producing a more clearly dened character. The standard typewriter ribbon equipment automatically withdraws the ribbon from contact with the stencil as soon as the pressure of the type face is released by the retraction of the type bar so that the ribbon is automatically withdrawn from contact with the stencil immediately following each character. With the use of the ribbon, the surface of the stencil is at all times ex- `posed for the purpose of correction of the stencil in the same quick and easy way in which corrections of ordinary typewriting are made and without the removal of the cover sheet from the stencil and likewise without the replacement of the cover sheet on the stencil, and readjustment of the stencil and cover sheet, in the typewriter,

Efforts have heretofore been made to cut stencutting of characters in the stencil with sufficient clearness to render the operation practical. The further fact of the combination of two (2) materials in such a ribbon renders the ribbon even less conformable to the type face and producing a still more undefined character.

I have found in practice that a character of desirable clearness of definition can be cut with a material of extreme toughness and flexibility and of a thickness of Aoco of an inch and that the increase in thickness of this material lessens the `deflniteness of the outline of the characterY and renders the operation less desirable and that if such thickness be increased beyond iooo or possibly 21/2/1000 of an inch, the outline 0f the character becomes so indefinite as to render the work undesirable if not Wholly impractical, and I have therefore produced a ribbon of tough and flexible or elastic material of substantially $6000 of an inch in thickness and of size-and form adapted for use in place of the standard or commonly used typewriter ribbons on the ordinary typewriter machine, such material being uninked and, if desired, tinted, or pigmented, by any suitable means for the entire elimination of glare or reflection,

In order to prevent distortion of the ribbon by repeated cutting of characters therethrough by the type faces and in order to strengthen and prolong the life of the ribbon, I have further provided reinforced edges of such ribbon formed preferably of additional layers of the material from which the ribbon itself is made, thus producing a ribbon with the required thinness of body throughout the area that is contacted by the type face but having edges of a suiiicient thickness of material to reinforce and strengthen the ribbon and prevent distortion thereof.

Under many business conditions, it is desirable to equip a typewriter with a ribbon which can b used either for ordinary typewriting or for stencil cutting and in order to meet the requirements of such business conditions, I have produced a ribbon havingv substantially one-half of its width formed of ordinary inked fabric and substantially the other half formed of tough, flexible or elastic material of approximately jAoco of an inch in thickness throughout the type-face-striking area of the ribbon and with the thickened, reinforcing edge, above described, on the outer edge of such half of the ribbon. The reinforcing of the inner edge of such thin half of the ribbon is accomplished by suitably connecting the fabric portion and the thin portion of the ribbon as, for example, by overlapping the two and thus using the attached fabric for reinforcement of the inner edge of the thin portion of the ribbon, thus providing a stencil cutting ribbon of my improved type throughout onehalf of the width of the ribbon and ordinary inked fabric ribbon throughout the other half of the width thereof. By the use of sucha product, the ribbon may be shifted l with ordinary typewriter equipment so as to bring either the inked or uninked portion within the area contacted by the type face.

The ends of typewriter ribbons are commonly provided with a hole or slit which is engaged over a hook provided on the ribbon spool. The ordinary fabric ribbon is sufficiently thick and strong so that it will not tear out of such engagement with such hook when pulled or stretched in common use. The exceedingly thin ribbon which I have produced would be in danger of tearing under such conditions unless additionally reinforced and to meet this condition, I have provided an additional reinforcement of any suitable material overlying the entire width of the ribbon adjacent the hole or slit in the end of the ribbon for attachment to the hook on the ribbon spool. This reinforcement may be of any suitable length, provided that it is shorter than the distance from the hook on the ribbon spool to the place where the type face strikes the stencil.

The instant invention is not concerned with the exact nature of the material employed in the strip I5, so long as such material has the qualities and characteristics hereinafter specified. As will be readily apparent, the material forming the strip I must be relatively very thin and highly flexible, so that the strip may promptly and accurately conform with the outline of the type face I2 or other cutting agent as the latter impinges against the strip for penetration through and cutting effect on the stencil body I4. Further, the material forming the strip I5 must be sufficiently tough to prevent its being cut through under the action of the type face thereon, must be resistant to wear so that the strip may be v repetitiously used in the cutting of successive stencils, must present a smooth, imperforate surface to the stencil body Il so as to preclude the possibility of adherence developing between said strip and margins of the stencil cuts, and must have such strength and resilience as will permit tensioning of the strip for feeding purposes across and in the desired relationship with the stencil assembly. The strip I5 may or may not be transparent, and may, perhaps advantageously, be pigmented or colored for ready contrast with the stencil surface, and said strip I5 is so mounted and arranged as to present a new portion of its surface to the impingement of successive type bars as actuated for lcutting'eifect on the stencil. The material obtainable on the market under the name fPliofilm also known as Plioform, being -a rubber derivative or a rubber composition chosen v from the group consisting of rubber hydrochloride, rubber hydrobromide and rubber hydroiodide, is one product which answers the requirements for the strip I5 of the present invention v as to thickness and characteristics.

illustrating the method, structure and product which I have generally described, I refer to the drawing in which the platen of the typewriter is conventionally illustrated at I0, the type bar at It will, of course, be understood that Figs. 9, l0 and l1 are greatly exaggerated as to thickness. The actual thickness of the ribbon i5 is, as above stated; substantially V1000 0f an inch and the thickness of the reinforcing edges i5a is preferably substantially 3/1000 of an inch, that is to say, each Vreinforcing edge is substantially 71000 of an inch in thickness in addition to the thickness ofthe ribbon itself. The comparative thickness of my improved ribbon I5 and the fabric ribbon I I is clearly illustrated at Fig. ll.

At' Fig. 5 I have illustrated an alternative structure comprising-a ribbon I5 of my improved type to the end of which is attached a ribbon I1 of inked fabric. Such a ribbon may be used on an ordinary typewriter for alternately cutting stencils or doing ordinary typewriting by winding the ribbon forward or backward on the ribbon spools until the desired portion of the ribbon comes into the type-striking area.

At Fig. 6 I have conventionally illustrated a' vcombination ribbon in which the upper longitudinal half is formed of the usual inked fabric and the lower longitudinal half is formed in accordance with the present invention. This illustration is conventional and does not disclose the reinforcement on the outer edge of ribbon I5 nor any reinforcement on the inner edge of such` 4 ribbon.

It will be understood that the ribbon I5 may be used to obtain practical results in its simple form and without reinforcement but vthe reinforcement of the character described markedly increases the stability and life of the ribbon and makes its use much more economical and practical.

Changes, variations and modifications in the specific character of the material employed and in the structure thereof may be had and obvious alternative equivalents may be used without in any manner departing from the spirit of the invention, and I am not to be limited by details illustrated or described but solely by the scope of the appended claims. I

spool is indicated at I9 and the reinforcing backing to strengthen the ribbon surrounding the hole ll isshown at I8 in Fig. 9.

The reinforced edges of a simple typewriter l. A new article of manufacture, namely a ribbon, for typewriters and like machines, composed of two longitudinally parallel strips, one of said strips being -inked fabric and theother strip being a stencil-cutting strip of a thinner, smooth, flexible, imperforate and uninked material and having its inner edge reinforced by an attachment to the fabric strip. y

' i 2. In a ribbon as defined in claim 1, the -re- Fig. l1, where the overlapping of my improved inforcement of the inner edge of the stencil cutting strip being accomplished by overlapping attachment to the edge ofthe fabric strip.

3. In a ribbon as defined in claim l, the outer edge of the said stencil cutting strip being reinforced by thickening of material thereof along said outer edge.

y 4. In a ribbon as defined in claim l, the uninked strip material being not to exceed 21/2 thousandths of one inch in thickness.

. MOE I. AARON. 

